NEC ECC: Option B (further question) what is remeasured?

Thank you for your reply. However, my question is, with a Z Clause deleting CE Clause 60.1 (13), when the reduce excavations are complete can we claim the quantity in the Price List without remeasuring, i.e. are we entitled to the full quantity in the Price List whether more or less is excavated and removed off site.

To answer this it is important to look at the basic principles.
Clause 20.1 - The Contractor Provides the Works in accordance with the Works Information.
The Price List is for payment purposes only.
Clause 50.3 - The amount due is… the price for work done to date.
Therefore your claim should be accordance with the work done to date as required by the Works Information.
If the Works information has lesser a quantity than the price list, you do not complete more work as you only complete what the Works information instructs you to complete.
Deleting clause 60.1(13) does not take away from the requirement to only complete the Works in accordance with the Works Information. Although the difference in quantities is not a Compensation Event it will essentially be presented as a re-measure.

As per Declan comment above - you get paid for what you do. With option B the Contractor is not taking the risk of errors in the (assumed) quantities.

Extra point of note is clause 60.4 that say significantly more/less (defined as more/less than 0.5% of the Prices st the Contract Date) then the extra over/under over will be assessed as a compensation event.
If you only did half the quantity it might mean that the cost per unit would have been more, and this clause allows you to reassess that (but only for the amounts outside of the 0.5% threshold)